Jack



May 25, 1954 J. M. BARosKo 3,134,232

JACK

Filed 00V 2. 1961 2 sheets-sheet 1 /4/ f@ f4 j A A May 26, 1964 J. M.BARosKo JACK 2 Sheets-Sheet 2 Filed Oct. 2. 1961 INVENTOR.

United States Patent O of Delaware Filed Uct. 2, 1961, Ser. No. 142,26911 Claims. (Cl. 60-52) This invention relates to an improvement in thehydraulic jack art, and more particularly to an improved multispeedhydraulic jack.

The present invention is directly related to hydraulic jacks in whichcontrol means are provided to cause the power applying ram to travelrapidly when approaching a load and to thereafter slow down and developthe necessary power as the load is applied. In such apparatus the changefrom high to low speed travel must be effected positively andautomatically. Several devices have been previously proposed toaccomplish the foregoing results. This invention provides new andimproved apparatus for obtaining automatic and positive two-speedplunger travel; and, in addition, provides stroke controlling meanswhich can be utilized to positively limit the length of travel of thejack ram and prevent continued application of excess power to the jackwhen a predetermined jack displacement has been obtained.

The primary object of the present invention is to provide means topositively control the displacement of the ram of a hydraulic jack. Itis another object of this invention to provide an improved two-speedhydraulic jack in which the length of travel of the jack ram isautomatically and effectively controlled. A further object is to providejack control means to prevent continuous excess power application to thejack after a predetermined jack position has been attained. Stillanother object of the present invention is to provide a multispeed,hydraulically actuated, power applying device having an improved designwhich is automatic and reliable in operation; yet compactly and sturdilyconstructed to insure maximum life. Other objects and advantages of theinvention will appear in the following detailed description in whichreference is made to the accompanying drawing wherein:

FIGURE 1 is a side elevational view in section showing an illustrativeembodiment of the present invention;

FIGURE 2 is a sectional view taken along the line 2 2 in FIGURE l;

FIGURE 3 is a sectional View taken along the line 3-3 in FIGURE l;

FIGURE 4 is a side elevational View, in section, of a portion of theapparatus shown in FIGURE l in another operative position; and

FIGURE 5 is a side elevational View, in section, of the apparatus shownin FIGURE 1 with all of the valving and uid passages revolved into thesame plane in order to illustrate the complete operationalsequence.

Referring now to the drawings, the illustrative embodiment of the jackcomprises a base member in the form of a casting and a capmember 12which are spaced by a cylindrical outer tube 14. A cylindrical sleeveelement 16 of smaller diameter than the cylinder element 14 isconcentrically mounted therewithin and denes a chamber 18 therewith.vThe chamber 18 provides a uid reservoir for jack actuating hydrauliclluid.y

Threaded end portions 20, 22 of the sleeve element 16 are threadablysecured in threaded openings 24, 26 in the cap member and the basemember, respectively. In this manner, the cap 12' and outer cylinder 14are rigidly secured to the base member 10. A ram element Sliis slidablysupported within a central bore 32 in the capY 12 and extends inwardlywithin the sleeve 16 and defines a chamber 34l therewith. A passage 38in the cap conicc nects the chambers 18 and 34 for a purpose to behereinafter described. The ram element is commonly referred to as a jackplunger or ram in the hydraulic jack art. The outer end 35 of the ram isadapted to abut and transfer power to a Work surface. The ram isprovided with a central bore 36 and terminates in a reduced end portion39. A piston forming annulus 40 is secured on the reduced end portionalong with a packing 42 which divides the chamber 34 into upper andlower fluid cavities. A tube 44 is mounted Within the central bore 36 ofthe ram.

' The tube is threadably engaged at one end 46 within a threaded bore 48in the base member 10 and is threadedly engaged at the other end 50 withan enlarged piston head 52. A central bore 54 in the piston headcornmunicates with the central bore 56 of the tube 44. The piston 52 is-slidably engaged with the wall of the central bore 36 and conventionalsealing means 56 divide the bore 36 into upper and lower lluid cavities.

Pump means are mounted in the base 10 and comprise a piston rod 60reciprocably mounted in a chamber 62. The inner end of the piston rod isreduced in diameter at 64 to provide a seat for packing means 66 whichare secured thereon by a nut assembly 68. The other end of the pistonrod is connected to drive link means 70, or the like, for actuation byany conventional power source. The chamber 62 terminates in a passage 72which communicates with a chamber 74. The chamber 74 is connected at oneend by a passage 76 to a passage 78 which communicates with the fluidreservoir 18 through a lter element 80. The passage. 76 is controlled bya ball-type valve 82 which is normally biased to a closed position by aspring element S4. The other end of the chamber 74 communicates with achamber 86 through a ball valve 88 which is normally biased to a closedposition by a spring element 90. The chamber 86 is connected by apassage 92 to the passage 56 in the tube 44. In addition, the chamber 86is connected through a ball valve 94, normally biased to a closedposition by the spring element 90, and a passage 96 to a passage 98which communicates with a chamber 19t) at the rear of the piston 40.

A release valve 104 of conventional design is mounted in a bore 106which communicates with'the chamber 86 by a passage 168 through a valve110. A tube release plunger 112 is slidably mounted in a release stem114 through which the valve can be moved away from closing engagementwith the passage 108. The release valve 110 connects the passage 108 toa passage 115 which communicates with the fluid reservoir 16 as shown inFIGURE 3. An overload valve 117 controls communication from a chamber116 and a passage 118 to the reservoir through a passage 120. Theoverload valve includes a ball element 122 which is biased to a normallyclosed position closing the passage 118 by means of a sleeve124 biasedinwardly by a spring element 126. As shown in FIGURE 5, the chamber 116communicates with the pump inlet passage 72 and with a chamber 130through a passage 132 and spring-biased ball valve 134. The chambercommunicates with the piston chamber 100 through a passage 133. Thechamber 100 and the central bore 36 also are connected by a passage 135and a chamber 136 to the reservoir through a ball valve 138 and passages140, 141 as shown in FIGURES 2 and 3. The ball valve 13S is biased to aclosed position by a closed position by a spring element 142. Thereservoir 16 is connected to a ller plug 150 by a passage 152.

Stroke control means are provided to positively limit the outwardmovement of the ram and comprise a sleeve element 16@ which is slidablymounted on the ram and has an inwardly opening tapered groove 162. Aball valve 164 is mounted in a valve seat 166 provided in the ram andcontrols a passage 168 which communicates with the chamber 36. A springclement 179 is concentrically mounted on the ram and abuts the sleeve16h at one end and the piston annulus di? at the other end. The spring17) normally biases the sleeve 165i forwardly to a position whereat thetapered groove 162 forces the ball valve 164 inwardly onto the seat 166to close the passage 168. As shown in FIGURE 4, the end face 172 of thesleeve 16) is adapted to engage an abutment surface, such as the surface174 provided in the end of the cap member 12, during outward movement ofthe ram. The sleeve lo@ will be moved rearwardly against the bias of thespring 17 0 to position an enlarged portion of the tapered groove 162over the ball valve 164 and permit high pressure duid in the passage 168to open the valve and escape into the upper end of chamber 34 throughthe passage 180 provided in the sleeve element. High pressure fluidescaping from the passage 18@ is returned to the reservoir 18 throughthe passage 3S in the end cap 12.

VIn operation with the parts in the position shown in FIGURE l, the pumpdi) is drawn outwardly in the pump chamber 62 and draws a quantity ofhydraulic fluid from the reservoir 18 through the iilter and thepassages 76, '78, past the ball valve 82 into the chamber 74, andthrough the passage 72. When the piston rod 6i) reaches the end of itsstroke and starts to return, uid is displaced from the pump chamberthrough the passage 72 into the chamber 74. The ball valve 22 isreseated by the spring element 84 and the pressure of the fluid in thechamber 74 to seal the passage 76. The fluid pressure in the chamber 74-moves the ball valve 3S away from its seat to open the chamber 74 to thechamber 86. Fluid flows from the chamber 74 and the chamber S6 throughthe passage 92 to the interior of the sleeve S6 and outwardly throughthe passage 54 in the valve head 52 to ll the chamber 58 and exert aforce on the ram 30. The high pressure force exerted by the lluid in thechamber b on the ram causes rapid outward movement thereof. As the rammoves outwardly, the chamber 1th@ is enlarged and creates a suctionwhich opens the ball valve 138 to permit hydraulic fluid from thereservoir 1S to flow into the chamber 161) through the passages 14:19,141, the chamber 136, and the passage 135. The pressure diiferentialbetween the chamber lilll and the uid reservoir 1S is large enough sothat the chamber 1d@ will remain full of fluid as the plunger movesrapidly outwardly. When the end surface 3S oi the ram encounters theload, pressure is built up in the chamber 1d@ by high pressure fluidbeing pumped from the chamber 62 into the chamber 116 until the ballvalve 134 opens and permits the high pressure fluid to ow into thecylinder cavity lili) through passage 133. Thereafter the ram may bemoved against the load by the build up of high pressure fluid within thechamber 106.

When the ram reaches a predetermined extended posil tion, as shown inFIGURE 4, the sleeve element 166i will come into abutting engagementwith the abutment surface 174 and cause the sleeve to be movedrearwardly against the bias of the compression spring 170. Rearwardmovement of the sleeve permits the ball valve 164 to be opened byaccumulated high pressure in the chamber 100 which aiso fills thechamber 36. The high pressure iiuid will be bypassed through the passage168 in the ram and the passage 13% in the sleeve through the passage 38into the fluid reservoir 1S. ln this manner, when the ram has reached apredetermined stroke position, as determined by the location of theabutment surface 174, any excess high pressure duid which would tend tomove the ram beyond the predetermined position is bypassed through thepassage 158. Accordingly, actuation of the pumping means may becontinued and the pumping means may continue to pump fluid into thechambers 1% without causing any damage to the equipment; and yet,maintain a predetermined load on the ram to support the load in theextended position. When the release valve 119 is actuated through therelease control 112, high pressure fluid in the chamber 1d@ will bevented through the passages 92, 9S, to chamber 36 and passage 108. Thepassage returns the iluid to the fluid reservoir and the ram returns tothe original position whereupon the apparatus is ready for anothercycle.

1t is contemplated that the abutment surface 174 can be provided at anyposition along the path of movement of the ram by the provision of anadjustable abutment surface which may be fixed to the inner periphery ofthe sleeve element 16 at any desired position. Although, the ball valve16d and slide sleeve lei) are particularly well adapted for controllingthe ram extension and provide advantageous results, it is contemplatedthat other alternative valve means might be utilized. It is intendedthat other modications and changes in the details of construction andthe arrangement of the parts embodying the principles of theinventionare to be included within the scope of the invention, as denedby the appended claims, except insofar as limited by the prior art.

What is claimed is:v

1. In a two-speed hydraulic jack, a base member, a cap member, hollowpiston means connected to said base member and extending therefrom,reciprocable ram means having a central bore and piston means secured tothe lower end thereof, said ram means being reeiprocably supportedwithin and extending through said cap member, said hollow piston meansbeing slidably received within said central bore, cylinder meanssurrounding and slidably supporting said piston means on said ram means,a iluid reservoir, passage means connecting said fluid reservoir to saidcentral bore and said cylinder means, pump means to iirst deliver Huidunder pressure to said central bore through said hollow piston means andsubsequently to deliver fluid under pressure to said cylinder means, abypass port means interconnecting said fluid reservoir and said centralbore and said cylinder means above said piston means on said ram means,and valve means controlling iiow through said port means and preventingilow therethrough until said reciprocable ram-means reaches apredetermined extended position and thereafter bypassing excess iluidsupplied to said central bore from said pumping means which tends tofurther extend said ram means to said reservoir, said valve means beingspaced between said cap member and said piston means on said ram meansand being completely separate therefrom and comprising a valve membermovable substantially transversely to the path of movement of said rammeans between an open position and a closed position relative to saidbypass port means, and valve actuating means axially reciprocable in apath parallel to the path of movement of said ram means to move saidvalve member between said open position and said closed position.

2. The jack apparatus as defined in claim 1 and wherein said valve meansis responsive to the position of said ram means and operableautomatically when said ram means reaches a predetermined position.

3. The jack means as defined in claim 1 and wherein said valve actuatingmeans comprises a control sleeve slidably mounted on said ram means andbeing movable therewith, spring means connected to said control sleeveto normally bias said control sleeve to a valve closing position, andabutment means located in the path of movement of said sleeve means withsaid ram means at a predetermined position whereby said sleeve meanswill engage said abutment means and be displaced against the bias ofsaid spring means relative t0 said ram means to open said valve meansand bypass said excess ram actuating fluid to said reservoir.

4. In a jack, cylinder means, an extendable ram means having a pistonassembly reciprocably mounted in said cylinder means, a liuid reservoir,operating passage means connecting said fluid reservoir to said cylindermeans, valve means controlling flow of lluid between said cylinder meansand said uid reservoir, pump means to pump fluid from said reservoirinto said cylinder means to extend said ram means, bypass passage meansconnecting said cylinder means to said uid reservoir to provide a bypassfor returning iluid from said cylinder means to said lluid reservoir,valve means mounted on and movable with said ram means for controllingsaid bypass passage means, said valve means comprising a sleeve membermovably mounted on said ram means for movement between spaced positionsand being spaced from said piston assembly, a valve movable to an openbypass position during movement of said sleeve member to one spacedposition and movable to a closed bypass position during movement of saidsleeve member to the other spaced position, means to normally bias saidsleeve member to said other spaced position, and means located inengaging alignment with said sleeve member in a predetermined extendedposition of said ram means and adapted to engage and displace saidsleeve member toward said one position to bypass uid thereafter tendingto further extend said ram means.

5. The invention as defined in claim 4 and wherein a portion of saidbypass passage means extends through said ram means, a valve seatprovided in said bypass passage in said ram means, a valve freelyassociated with said valve seat and having a portion located forengagement with said sleeve member, and control means provided on saidsleeve member and being engageable with said valve to normally seat saidvalve on said valve seat in said other position and to permit movementof said valve away from said valve seat in said one position in responseto increases in pressure of said fluid tending to further extend saidram means.

6. The invention as defined in claim 5 and wherein said valve comprisesa ball valve having a portion continually extending outwardly beyondsaid ram means and said control means comprises a tapered slotaccommodating said portion of said ball valve and causing variableinward displacement of said ball valve toward said valve seat inresponse to movement between said ram means and said sleeve member.

7. In a jacking device, an extendable ram means, piston means mounted onsaid ram means, cylinder means engaging said piston means andreciprocably supporting said ram means, a fluid system including a pumpmeans and fluid reservoir connected to said cylinder means to causereciprocation of said ram means therein, fluid bypass passage meansconnecting said cylinder means to said luid reservoir, bypass passagecontrol means to prevent movement of said ram means beyond apredetermined extended position and maintain said ram means in saidextended position during continuous operation of said pump means andcontinuous delivery of iluid therefrom to said cylinder means, saidbypass passage control means comprising sleeve means separate from saidpiston means and carried by and movably mounted on said ram means, a rstportion of the bypass passage means being formed in said ram meansbeyond said piston means adjacent said sleeve means, a second portion ofsaid bypass passage means being formed in said sleeve means, said secondportion of said bypass passage means being connectible to the rest ofsaid bypass passage means communicating with said uid reservoir at apredetermined extended position of said ram means, valve meansconnecting said iirst portion of said bypass fluid passage and saidsecond portion of said bypass Huid passage, said valve means beingactuable between open and closed positions by relative movement betweensaid sleeve means and said ram means, spring means associated with saidsleeve means to normally maintain said sleeve means in a valve-closingposition, and abutment means engageable with said sleeve means at saidpredetermined position to displace said sleeve means relative to saidram means against the bias of said spring means and release said valvemeans for movement to said open position in response to excess uidpressures being applied to said ram means.

8. The invention as defined in claim 7 and wherein said second portionof said bypass passage means in said sleeve means comprises an annulargroove having a tapered wall portion engageable with said valve means,and said sleeve means being movable longitudinally o f said ram means tocause progressive engagement and disengagement of said tapered wallportion with said valve means as said sleeve means moves relative tosaid ram means.

9. In a jacking device, cylinder means, an extendable ram meansreciprocably mounted in saidpcylinder means, one end of said extendableram means extending beyond said cylinder means for engagement with aload and the other end of said extendable ram means having a pistonassembly dividing said cylinder means into upper and lower chambers',said ram means having a smaller outer diameter than the inner diameterof said cylinder means and thereby defining the upper chamber as anannular cavity, means to apply high pressure fluid against said pistonassembly in the lower chamber to cause extending movement of said rammeans within said cylinder means, bypass passage means connecting saidcylinder means to said uid reservoir whereby high pressure fluid beingapplied to said piston assembly may be bypassed to said fluid reservoir,a rst portion of said bypass passage means comprising a passageextending through said ram means from the area adjacent said pistonassembly in the lower chamber to said annular cavity of the upperchamber between said ram means and said cylinder means, a second portionof said bypass passage means including a passage portion connecting saidannular cavity of the upper chamber between said ram means and saidcylinder means to said uid reservoir and having an inlet opening to saidannular cavity longitudinally spaced from the outlet opening of said rstportion of said bypass passage into said annular cavity, valve meansmounted in said iirst portion of said bypass passage and being movabletherein from a passage-closing position to a passage-opening position,and valve control means slidably mounted on said ram means in saidannular cavity and being movable there- With and relative thereto tomaintain said valve means in the closed position until said ram meansreaches a predetermined extended position, said valve control meansbeing operable in said predetermined position to connect said firstportion of said bypass passage means to said second portion of saidbypass passage means by sliding movement relative to said ram means.

10. The invention as dened in claim 9 and wherein a third portion ofsaid bypass passage is provided in said valve control means, said thirdportion of said bypass passage communicating with said rst portion ofsaid bypass portion through said valve means, said thirdv portion ofsaid bypass passage having an outlet port formed in a side surface ofsaid valve control means, said side surface having sliding abuttingengagement with the inner peripheral Wall of said cylinder means andclosing said outlet port until said predetermined position is reached,said third portion of said bypass passage being connectible to saidsecond portion of said bypass passage when said ram means reaches saidpredetermined extended position to permit excess high pressure uid beingappliedto said piston assembly to flow through said iirst portion ofsaid bypass passage past said valve means through third portion of saidbypass passage in said control means to said second portion of saidbypass passage and said fluid reservoir.

ll. The invention as dened in claim l0 and wherein: said valve controlmeans comprises a sleeve member in the form of an annular ring, saidannular ring having a width substantially equal to the width of saidannular cavity between said ram means and said cylinder means, anannular groove formed about the inner periphery of said annular ring andopening toward said ram means, the distance between said valve seat andsaid ball valve being less than the diameter of said ball valve so thata portion of said ball valve protrudes radially outwardly beyond theouter peripheral surface of said ram means, said groove having a ballabutment surface tapering from a portion of maximum width whereat saidball valve may move freely oi of said seat to a portion of minimum WidthWhereat said ball valve is held in abutting engagement with said valveseat, movement of said annular ring relative to said ram means beingconfined to substantially the longitudinal length of said groove byabutting engagement With said ball valve, said outlet opening in saidthird portion of said bypass passage being formed by a radiallyextending bore intersecting said groove, spring means concentricallymounted on said ram means between said piston assembly and said annularring and engaging and biasing said annular ring to a Valve-closingposition, and abutment means provided at the upper end of said cylindermeans to engage said annular ring in said predetermined position andcause sliding displacement thereof against the bias of said compressionspring to release said ball valve and permit the flow of high pressurefluid through said bypass passage to said reservoir.

References Cited in the le of this patent UNITED STATES PATENTS2,409,335 Stephens July 28, 1936 2,520,426 Mueller Aug. 29, 19502,625,796 Traut Jan. 20, 1953 2,715,512 Miller et al Aug. 16, 19552,851,011 Chasser Sept. 9, 1958 2,863,285 Pomeroy Dec. 9, 1958 UNITEDSTATES PATENT OFFICE CERTIFICATE CF CORRECTION Patent Noo 3,l34232 May26U l964 John M Barosko It is hereby certified that error appears in theabove numbered patent requiring correction and that the said. LettersPatent should read as Corrected below.

Column 6Y line 63, after "whereins" insertI said valve means comprises avalve seat provided in said first portion of said passage means and aball valve freely associated with said valve seat, and

Signed and sealed this 12th day of January 1965.

(SEAL) Attest:

EDWARD J. BRENNER Commissioner of Patents ERNEST w.: swIDER ttestngOfficer

4. IN A JACK, CYLINDER MEANS, AN EXTENDABLE RAM MEANS HAVING A PISTONASSEMBLY RECIPROCABLY MOUNTED IN SAID CYLINDER MEANS, A FLUID RESERVOIR,OPERATING PASSAGE MEANS CONNECTING SAID FLUID RESERVOIR TO SAID CYLINDERMEANS, VALVE MEANS CONTROLLING FLOW OF FLUID BETWEEN SAID CYLINDER MEANSAND SAID FLUID RESERVOIR, PUMP MEANS TO PUMP FLUID FROM SAID RESERVOIRINTO SAID CYLINDER MEANS TO EXTEND SAID RAM MEANS, BYPASS PASSAGE MEANSCONNECTING SAID CYLINDER MEANS TO SAID FLUID RESERVOIR TO PROVIDE ABYPASS FOR RETURNING FLUID FROM SAID CYLINDER MEANS TO SAID FLUIDRESERVOIR, VALVE MEANS MOUNTED ON AND MOVABLE WITH SAID RAM MEANS FORCONTROLLING SAID BYPASS PASSAGE MEANS, SAID VALVE MEANS COMPRISING ASLEEVE MEMBER MOVABLY MOUNTED ON SAID RAM MEANS FOR MOVEMENT BETWEENSPACED POSITIONS AND BEING SPACED FROM SAID PISTON ASSEMBLY, A VALVEMOVABLE TO AN OPEN BYPASS POSITION DURING MOVEMENT OF SAID SLEEVE MEMBERTO ONE SPACED POSITION AND MOVABLE TO A CLOSED BYPASS POSITION DURINGMOVEMENT OF SAID SLEEVE MEMBER TO THE OTHER SPACED POSITION, MEANS TONORMALLY BIAS SAID SLEEVE MEMBER TO SAID OTHER SPACED POSITION, ANDMEANS LOCATED IN ENGAGING ALIGNMENT WITH SAID SLEEVE MEMBER IN APREDETERMINED EXTENDED POSITION OF SAID RAM MEANS AND ADAPTED TO ENGAGEAND DISPLACE SAID SLEEVE MEMBER TOWARD SAID ONE POSITION TO BYPASS FLUIDTHEREAFTER TENDING TO FURTHER EXTEND SAID RAM MEANS.